Question: Solve for $x$ : $2\sqrt{x} + 9 = 7\sqrt{x} + 10$
Explanation: Subtract $2\sqrt{x}$ from both sides: $(2\sqrt{x} + 9) - 2\sqrt{x} = (7\sqrt{x} + 10) - 2\sqrt{x}$ $9 = 5\sqrt{x} + 10$ Subtract $10$ from both sides: $9 - 10 = (5\sqrt{x} + 10) - 10$ $-1 = 5\sqrt{x}$ Divide both sides by $5$ $\frac{-1}{5} = \frac{5\sqrt{x}}{5}$ Simplify. $-\dfrac{1}{5} = \sqrt{x}$ The principal root of a number cannot be negative. So, there is no solution.